Patent GB-157972-A (GB)
Title: Improvements in and relating to the visible representation of electric signals
IPC: B66B19/06
Filed: 1921-01-10
Abstract: 157,972. Neufeldt & Kuhnke. May 12, 1919, [Convention date]. Void [Published under Sect. 91 of the Act]. Mine signalling systems; order and order-type apparatus.-A visual indicating device for use where the signals are characterized by the time intervals between the received impulses has indicating members moved into a display field so as to be spaced apart in accordance with the time intervals between the impulses. The arrangement is described as specially applicable to mine signalling systems but may be used to indicate Morse signals, one impulse representing a dot, for example, and two impulses in quick succession representing a dash. The indicating members may be directly visible, or may reflect light from a suitable source into corresponding positions in a display field. In one form, indicating members such as flags are carried at the upper ends of arms 4 freely mounted on a shaft 2 which is given uniform rotation by means not shown. The arms do not partake of the rotation of shaft 2 until selectively coupled thereto by signalling impulses. For this purpose, shaft 2 carries a frame 3 in which are mounted pins 7 adapted to engage extensions 6 on the arms 4 so that the arms then partake of the motion of frame 3 and shaft 2. Pins 7 are controlled by cams 11 on a shaft 12 mounted in frame 3 and stepped round by signal impulses energizing a pawl-operating magnet 14, which is mounted on frame 3. The cam discs are so formed that pins 7 are moved into engagement successively as shaft 12 is stepped round. The first signal impulse couples up the first arm, which is then moved by shaft 2 along an elongated display field shown as a window 5a. When the second impulse arrives, the second arm is coupled up, and follows the first arm in its movement across the field, the space between the arms depending on the interval between the impulses. Succeeding impulses operate successive arms in similar manner, so that the characteristics of the signal' are visible from the relative positions of the arms along the field. When a signal has been given, its cancellation, which may be controlled by the winding engine, is effected by energizing magnet 15, which withdraws the pawl 20 and detent 21 from engagement so that shaft 12 is returned to initial position by a spring 13, and by energizing a solenoid 23 which operates, through a rack and pinion, an arm 28 which brings the arms 4 back to zero position. An alternative form of apparatus is described in which the indicating members are mounted on a horizontal shaft so as to extend therefrom horizontally and side-by-side. A selector finger, traversing above the indicating members, is oscillated by each signal impulse to depress into the display field the indicating member over which it happens to be. The finger is traversed by a 'band connected to a carriage, moved in one direction by a pulley through a ratchet wheel and clutch, and returned when closure of the cancelling circuit disengages the clutch, by a weight. A solenoidoperated arm restores the indicating members to normal position.